A gearshifting device of the aforementioned kind is known from DE 102 49 074 A1 and serves to shift an automatic transmission, which exhibits an additional manual shift function. The gearshifting device allows various automatically shiftable drive positions, such as “P,” “R,” “N,” “D,” to be preselected by pivoting a selector lever into a first gearshift gate. The selector lever can be shifted by way of the cross gate from the first gearshift gate into a second gearshift gate, in which the individual, manually shiftable gears can be preselected. The manually shiftable gears in the second gearshift gate are shifted by pivoting the selector lever in two opposite directions—for example, in the direction of travel and in the direction opposite the direction of travel. This action takes place by just tapping the selector lever, which induces a so-called plus sensor and minus sensor to respond and they in turn initiate an upshift or downshift of the manual transmission gears.
For safety reasons the gearshifting device prevents a shift between certain drive positions in the first gearshift gate by means of a lock, which can be overcome by activating an activating element. This shift lock is not desired in the second gearshift gate, which provides the additional manual gearshift function, because it is precisely in the second gearshift gate that a slight tap or pivoting of the selector lever is supposed to initiate the upshift or downshift of the manual gear speeds.
In order to prevent the selector lever from moving freely in the first gearshift gate with the automatic shiftable drive positions, but at the same time to make it possible to move the selector lever freely in the second gearshift gate, the gearshifting device has an intermediate piece, which is supported relative to the housing in the first gearshift gate and forms a stop for the selector lever. The intermediate piece is disposed on a connecting link, on which the selector lever is mounted in a pivotable manner. On shifting from the first gearshift gate into the second gearshift gate, the selector lever is pivoted together with the connecting link. In this way the intermediate piece in the gearshifting device would also form a lock for the selector lever even in the second gearshift gate. In order to prevent such a lock, the intermediate piece is mounted in a moveable manner on the connecting link; and the housing is displaced in such a manner that the selector lever can be moved freely in the direction of the second gearshift gate far enough that the manual gears can be shifted up or down. At the same time the intermediate piece is moved outwards by the selector lever. In order to guarantee that the intermediate piece will return again into its starting position, a spring element is provided.
Therefore, the gearshifting device employs relatively complicated technical measures to block the traversing path of the selector lever in the first gearshift gate and to be able to move the selector lever freely in the second gearshift gate.
Another gearshifting device equipped with an automatic transmission mode and additional manual transmission mode is known from EP 0 899 478 A1. The gearshifting device exhibits a shift lock, which for safety reasons prevents the selector lever of the gearshifting device from being shifted from one shift position into another shift position inside the gearshift gate. To this end the selector lever has a positioning bolt, which moves with the selector lever and strikes against the shift lock when the selector lever is moved in an attempt to shift. This shift lock is formed by a stop, which is configured on a side wall of the housing of the gearshifting device. For this purpose the side wall has a passage opening, of which the upper rim forms the stop. The profile of the opening rim is designed in such a manner that additional stops, forming the shift locks, are produced along the traversing path of the selector lever.
The gearshifting device has two such side walls with the selector lever situated between the side walls. In the selector lever's vertical starting position, in which the selector lever is located in the gearshift gate for the automatic transmission mode, the positioning bolt, which is coupled to the selector lever, is horizontally oriented and engages with each of its two ends in the opening of the side walls. In this position of the positioning bolt, the traversing path of the selector lever inside the gearshift gate for the automatic transmission mode is limited by at least one of the stops on the opening rim. If the selector lever is pivoted from the gearshift gate for the automatic transmission mode into the gearshift gate for the manual transmission mode, then the positioning bolt moves into an inclined position as a function of the pivot movement of the selector lever. In this position the positioning bolt engages with only its one end in the opening of the one side wall and with its other end has left the position of engagement with respect to the opening of the other side wall. In addition, the gearshifting device provides a relatively complex mechanism that is used to move the positioning bolt downwards in a straight line when the selector lever is pivoted. As a result, the positioning bolt with its end engaging in the one opening is moved downwards far enough that the pivot movement of the selector lever in the gearshift gate for the manual transmission mode is no longer limited by the one shift lock and, hence, the shift lock is deactivated. However, the pivot movement of the selector lever is limited by a shift lock that is located farther away.
In summary the gearshifting device resorts to relatively complicated strategies in order to provide, on deactivation of the shift lock, a traversing path for the selector lever that is adequate enough to impart to the driver of the vehicle a comfortable operating feeling.
Therefore, it would be desirable to have a gearshifting device for a transmission that exhibits a shift lock that can be activated and deactivated in a technically simple manner. Furthermore, when the shift lock is deactivated, the selector lever of the gearshifting device should be moveable over a traversing path that is sufficiently long to give a comfortable gearshifting feeling.